Remove unused variable

This variable was clearly for the print statement below, but then got
abandoned at some point.  Clean it up.

cppcheck found this as well.

Tested: Unused code

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I2d143f00dc6956c87ba77d5cbe1b96be631ca795
diff --git a/http/http_client.hpp b/http/http_client.hpp
index ca350c7..fe5ef8e 100644
--- a/http/http_client.hpp
+++ b/http/http_client.hpp
@@ -612,7 +612,6 @@
         ioc(iocIn),
         id(idIn), destIP(destIPIn), destPort(destPortIn)
     {
-        std::string clientKey = destIP + ":" + std::to_string(destPort);
         BMCWEB_LOG_DEBUG << "Initializing connection pool for " << destIP << ":"
                          << std::to_string(destPort);